This invention relates to apparatus for counting drops and this particular application for counting drops from a burette to obtain a measure of the amount of liquid reactant (titrant) added to an unknown solution.
Drop counters are known. These drop counters use apparatus directing a light beam across a chamber toward a light sensor on the other side of the chamber. When a drop falls through the chamber the light beam is interrupted, and thus providing an indication of the presence of a drop. See for example U.S. Pat. No. 4,181,130 to Bailey. Other known apparatus include a light source for directing a light beam toward a falling drop and include a beam detector located to detect a refracted light beam that has passed sidewardly out of a drop. See U.S. Pat. No. 5,982,289 to Kingsley, et. al.
There is a need for a compact drop counter which is reliable and not affected by ambient light or by conditions occurring when drops become fragmented.